Dependencies added for new jsonschema support

[Katherine Cox-Buday]

Nate Finch <nate.finch at canonical.com> writes:

> In support of my PR that adds an interactive mode for add-cloud, we needed to add
> jsonschema for the cloud configurations that can be inspected at runtime to generate the
> interactive queries.

Thanks for the great write-up, Nate. I've added it to the tech board agenda[1] and we should review tonight.

-- 
Katherine

[1] - https://docs.google.com/document/d/13nmOm6ojX5UUNtwfrkqr1cR6eC5XDPtnhN5H6pFLfxo/edit